Electrical testing apparatus for hermetically sealed refrigerator pump units



March 10, 1953 H. BUNKER" 2,631,187 ELECTRICAL TESTING APPARATUS FOR HERMETICALLY Filed March 18, 1949 SEALED REFRIGERATOR PUMP UNITS 2 SI'XEETS-'S1*!E3T l f) if ,z mi' "w" ll 0 I I I IN VEN TOR.

m. W Z M HMF N M" M S mmufiumm W 2 i F B r T. H. BUNKER SEALED REFRIGERATOR PUMP UNITS.

March 1 0, l 953 ELECTRICAL TESTING APPARATUS FOR HERMETICALLY Flled March 18 1949 Patented Mar. 10, 1953 UNITED STATES PATENT OFFICE Application MarchlS, 1949, Serial No. 8 2,932

2 Claims. IV

This invention relates to electrical testing apparatus, and one object thereof is the provision of a practical, useful andeificient yet simple testing unit for testing hermetically sealed refrigeration pump units.

The apparatus includes anammeter which is used to determine the common, runnin and starting poles or binding posts of the electric pump unit, thereby eliminating wire color schemes and the possibility of wrong connections through confused colors and disconnecte'd leads.

The above broad as well as additional and more specific objects will become-apparentin the following description, whereincharactersof reference refer to like-numbered-parts in'the accompanying drawings. It is to beno'ted that the drawings are intended solely for the purpose of illustration, andthat it is therefore neither desired nor intended to limitthe invention necessarily to any or all of the exact details shown except insofar as they may be deemed essential to the invention.

Referring briefly to the drawings, Fig. 1 is a perspective view of the self contained testing unit.

Fig. 2 is a schematic wiring diagram of the testing unit and its application and hook-up in testing a refrigeration pump unit Referring in detail to thedrawings, the numeral It} indicates a cabinet, housing, box or other suitable containerwhich maybe made of wood or any other suitable or" desired material. In the front wall or panel "of the box I9, shown at H, an ammeter I2 is visibly mounted. Also mounted in the panel II are a test lamp I3, a replaceable fuse I 4, and switches I5, I6, I'I, I8 and I9 whose functions are indicated by captions on the panel and which are shown schematically in Fig. 2. A plug-in line connector cord is shown at 20, leading from the box I 0, and leads 2I, 22, and 23 extending from the top of the box have on their ends battery clips 24 which, although not shown so, are preferably insulated. Captions on top of the box indicate the nature of each of these leads, and they are also shown in the wiring dia gram.

In Fig. 2 the numeral 25 indicates schematically the refrigerator housing and the numeral 26 indicates or represents the split phase or capacitorstart motor which drives the pump, not shown, the starting winding of the motor being shown at 2! and the running winding at 28. The common terminal of the two motor windings is shown at 29, the other terminal of the starting winding at 30 and the other running terminal at 3I.

As shown in the wiring diagram of Fig. 2, the on and off o'r'line switch I8 is of the single throw double-pole type, and the lamp switch I5 is of the double throw double-pole type. A jumper 32 connects one terminal 33 of the switch i5 diagonally with the opposite "pivot terminal 34 of the switch arm35, and another jumper 36 connects the terminal 31 of the switch I5 with the terminal 380i the switch I8; One line conductor 39 leads to the terminal 49 of the switch 18; the other line conductor}! leads through the fuse I4 to a terminal 42. From-the latter one lead 33 leads through the lamp I3'to the terminal 33, and another lead 44 leads to the" terminal 45 of the switch iii, the terminal 46 of the latter being idle. From the other pivot terminal 47 013 the switch I5-a lead 48conn'ec'ts with the terminal 49 of the switch I'8f A lead 5| leads into the ammeter I2 from the terminal 58 of the switch I8,- and the test lead 23 leads from the ammeter. A'- lead 52 connects the terminal'38 with a common point'53 from which one lead 54 extends to the pivot terminal 550i the arm'56 of the switch I'I, andanother lead 5'! leads to the terminal 58 of the switch I9 A capacitor 59 is, as shown, connected across the switch I6," and fromon'common' terminal 60 thereof a lead'fil'connects'to' the other pole 62 of theswitch I9; from the other common terminal 63 thereof a lead 64 connects with the other pivot terminal 65' of the switch I1." 'The latter is converted to a reversing switch by 1 means of the crossed jumpers 66 ands? cr'mn'ected at one end to the poles 68' and B9,- respe'ctively, and at the other end to the poles I9 and II, respectively. The test lead 2I extends from the pole 69, and the test lead 22 extends from the pole 68.

It is apparent that the reversing switch I! reverses the direction of rotation of the split phase or capacitor start motor by interchanging the running and starting leads 2i and 22.

In use, with the reversing switch in forward position, shown in Fig. 2, with the line switch It closed and the switch i5 open, the leads 22 and 23 are applied to the three terminals 29, 30 and 3! of the pump motor 25 in the three possible combinations, and that one which gives the lowest ammeter reading indicates that the remaining terminal is the common terminal 29. That is, when the leads 22 and 23 are connected to the terminals 30 and 3? the lowest ammeter reading of the three combinations is obtained, which signifies that the terminal 2-9 is the common terminal of the motor 26. Then the lead 23 is attached to the common terminal 29, and the leads 2| and 22 are attached to the two remaining poles 30 and 3|.

If the motor 26 then starts when the starting switch I9 is closed momentarily, then the operation is repeated with the reversing switch ii in reversed position, the ammeter reading being noted in both cases. That position of the switch 11 which gives the lower ammeter reading is then the one for correct rotation of the motor. In case the motor does not start in either position, a rhythmic back-and-forth movement of the switch 17 will often free the stuck pumpunit and initiate starting.

For ground or continuity tests for or through the motor windings or any part of the circuit, the switch l may be used as follows. It is to be noted that when this switch is thrown to the right, Fig. 2, the lamp I3 is in parallel with the test circuit and serves as a pilot light. When the switch is thrown to the left the lamp is in series with the line circuit, so that it will indicate whether any of the windings or circuits of the pump unit are continuous or open, with the leads 2|, 22 and 23, of course properly applied to the terminals of the motor 26.

The starting capacitors, 59 may also, in an obvious manner, he tested for efiiciency on the ammeter.

It is thus apparent that a very handy and practical test unit has been provided for the purposes set forth, which is simple and inexpensive in construction and operation and efficient in use.

Obviously, modifications in form or structure may be made without departing from the spirit or scope of the invention.

I claim:

1. An electrical testing apparatus for substan tially the purposes described comprising a double-pole single throw line switch having one pair of terminals thereof adapted to be connected to a power line, an ammeter having one terminal thereof connected to one of the other pair of terminals of said line switch, the other terminal of the ammeter having a test lead extending therefrom, a double-pole double throw reversing switch including a forward pair of terminals and a reverse pair of terminals and a pivoted switch arm, one of the pivot terminals of said reversing switch having a lead joining the same to the other of said other pair of terminals of said line switch, a single throw starting switch having one terminal thereof connected to said other of said other pair of terminals of said line switch, a lead connecting the other of said terminals of said 4 starting switch with the other of said pivot terminals of said reversing switch, a jumper connecting one of the forward terminals of the reversing switch with the diagonally opposite reverse terminal thereof, a jumper connecting the other for-- ward terminal of the reversing switch with the other of said reverse terminals, a test lead extending from one of said forward terminals of said re versing switch, and a test lead extending from the other of said forward terminals of said reversing switch, said test leads being adapted to be connected severally to the common terminal and the starting and running terminals of a split phase motor in three obvious combinations, said ammeter indicating its lowest reading in that one of said combinations wherein said first mentioned test lead is connected to said common terminal.

2. The apparatus set forth in claim 1, one of the conductors of said power line having a lamp in series therein, a second double-pole double throw switch, said conductor being broken adjacent said lamp thereby providing two juxtaposed ends, one of said juxtaposed ends having a lead connecting the same to one of the intermediate terminals of said second double-pole double throw switch, one terminal of one of the pair of end terminals of the latter switch having a jumper leading therefrom and joined to said conductor on the other side of said lamp, a lead connecting the other terminal of said one pair of end terminals of said latter switch with said other of said pair of terminals of said line switch, and a jumper connecting the other of said lastnamed juxtaposed ends to the other of said intermediate terminals of said second double-pole double throw switch.

THOMAS H. BUNKER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS OTHER REFERENCES.

Electric Motor Repair, by Rosenberg, published by Murray Hill Books, Inc, New York, 19 16. Pages 19, 21 and 44 in Illustrations Section. 

